Compare / Claude Sonnet 4.5 vs Gemini 3 Flash Preview
Claude Sonnet 4.5 vs Gemini 3 Flash Preview
7 results from 4 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | Claude Sonnet 4.5 | Gemini 3 Flash Preview |
|---|---|---|---|
| SimpleQA Verified (Epoch AI)reported | Correct answers% of questions | 30.7% | 66.8% |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 5.0% | 16.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.41 | 0.37 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 66.9 | 67.7 |
| Vectara Hallucination Leaderboardreported | Answer rate% of documents | 95.6% | 99.8% |
| Vectara Hallucination Leaderboardreported | Hallucination rate% of summaries | 12.0% | 13.5% |
| Vending-Bench 2reported | Money after a yearUS dollars | $3,838.74 | $3,634.72 |
Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.